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Journal articles on the topic 'Magnetosphere-ionosphere current systems'

Author: Grafiati

Published: 6 September 2023

Last updated: 31 July 2025

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1

Cowley, S. W. H., A. J. Deason, and E. J. Bunce. "Axi-symmetric models of auroral current systems in Jupiter's magnetosphere with predictions for the Juno mission." Annales Geophysicae 26, no. 12 (2008): 4051–74. http://dx.doi.org/10.5194/angeo-26-4051-2008.

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Abstract. We develop two related models of magnetosphere-ionosphere coupling in the jovian system by combining previous models defined at ionospheric heights with magnetospheric magnetic models that allow system parameters to be extended appropriately into the magnetosphere. The key feature of the combined models is thus that they allow direct connection to be made between observations in the magnetosphere, particularly of the azimuthal field produced by the magnetosphere-ionosphere coupling currents and the plasma angular velocity, and the auroral response in the ionosphere. The two models ar

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2

Rostoker, G., and F. Pascal. "Dependence of the response of the magnetosphere–ionosphere current systems on the preconditioning of the auroral oval and on the level of the solar–terrestrial interaction." Canadian Journal of Physics 68, no. 1 (1990): 74–80. http://dx.doi.org/10.1139/p90-011.

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It is now well accepted that the impulse response time of the magnetosphere to sudden changes in the interplanetary medium is of the order of 2 h with the shape of the impulse response function approximating a Rayleigh function with a peak near 50 min. In a recent study, Bargatze et al. (J. Geophys. Res. 90, 6387 (1985)) examined the response of the magnetosphere for varying activity levels and found that the impulse response function has two well-defined peaks for moderate activity and a single broad peak for low and high activity levels. They explain the two peaks in the response function as

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3

Cowley, S. W. H., and E. J. Bunce. "Corotation-driven magnetosphere-ionosphere coupling currents in Saturn’s magnetosphere and their relation to the auroras." Annales Geophysicae 21, no. 8 (2003): 1691–707. http://dx.doi.org/10.5194/angeo-21-1691-2003.

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Abstract. We calculate the latitude profile of the equatorward-directed ionospheric Pedersen currents that are driven in Saturn’s ionosphere by partial corotation of the magnetospheric plasma. The calculation incorporates the flattened figure of the planet, a model of Saturn’s magnetic field derived from spacecraft flyby data, and angular velocity models derived from Voyager plasma data. We also employ an effective height-integrated ionospheric Pedersen conductivity of 1 mho, suggested by a related analysis of Voyager magnetic field data. The Voyager plasma data suggest that on the largest spa

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Tsunomura, S. "Numerical analysis of global ionospheric current system including the effect of equatorial enhancement." Annales Geophysicae 17, no. 5 (1999): 692–706. http://dx.doi.org/10.1007/s00585-999-0692-2.

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Abstract. A modeling method is proposed to derive a two-dimensional ionospheric layer conductivity, which is appropriate to obtain a realistic solution of the polar-originating ionospheric current system including equatorial enhancement. The model can be obtained by modifying the conventional, thin shell conductivity model. It is shown that the modification for one of the non-diagonal terms (Σθφ) in the conductivity tensor near the equatorial region is very important; the term influences the profile of the ionospheric electric field around the equator drastically. The proposed model can reprod

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Neudegg, D. A., B. J. Fraser, F. W. Menk, G. B. Burns, R. J. Morris, and M. J. Underwood. "Magnetospheric sources of Pc1-2 ULF waves observed in the polar ionospheric waveguide." Antarctic Science 14, no. 1 (2002): 93–103. http://dx.doi.org/10.1017/s0954102002000627.

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Energy from the outer regions of the magnetosphere may be transferred to the polar ionosphere by plasma waves. A magnetometer array operated during the Antarctic winter observed Ultra-Low-Frequency (ULF) plasma waves in the Pc 1–2 (0.1–10.0 Hz) frequency range, propagating parallel to the surface of the Earth in a waveguide or duct centred at ∼300 km altitude in the ionosphere. These compressional fast mode plasma waves most likely originated in the outer magnetosphere as shear mode plasma waves guided along the geomagnetic field. The region of origin in the magnetosphere for the waves is not

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Ganse, Urs, Yann Pfau-Kempf, Hongyang Zhou, et al. "The Vlasiator 5.2 ionosphere – coupling a magnetospheric hybrid-Vlasov simulation with a height-integrated ionosphere model." Geoscientific Model Development 18, no. 2 (2025): 511–27. https://doi.org/10.5194/gmd-18-511-2025.

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Abstract. Simulations of the coupled ionosphere–magnetosphere system are a key tool to understand geospace and its response to space weather. For the most part, they are based on fluid descriptions of plasma (magnetohydrodynamics, MHD) formalism, coupled to an electrostatic ionosphere. Kinetic approaches to modeling the global magnetosphere with a coupled ionosphere system are still a rarity. We present an ionospheric boundary model for the global near-Earth plasma simulation system Vlasiator. It complements the magnetospheric hybrid-Vlasov simulations with an inner boundary condition that sol

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7

Tanaka, T. "Generation mechanisms for magnetosphere-ionosphere current systems deduced from a three-dimensional MHD simulation of the solar wind-magnetosphere-ionosphere coupling processes." Journal of Geophysical Research 100, A7 (1995): 12057. http://dx.doi.org/10.1029/95ja00419.

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Le, G., C. T. Russell, and K. Takahashi. "Morphology of the ring current derived from magnetic field observations." Annales Geophysicae 22, no. 4 (2004): 1267–95. http://dx.doi.org/10.5194/angeo-22-1267-2004.

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Abstract. Our examination of the 20 years of magnetospheric magnetic field data from ISEE, AMPTE/CCE and Polar missions has allowed us to quantify how the ring current flows and closes in the magnetosphere at a variety of disturbance levels. Using intercalibrated magnetic field data from the three spacecraft, we are able to construct the statistical magnetic field maps and derive 3-dimensional current density by the simple device of taking the curl of the statistically determined magnetic field. The results show that there are two ring currents, an inner one that flows eastward at ~3 RE and a

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9

Nichols, J. D., and S. W. H. Cowley. "Magnetosphere-ionosphere coupling currents in Jupiter’s middle magnetosphere: dependence on the effective ionospheric Pedersen conductivity and iogenic plasma mass outflow rate." Annales Geophysicae 21, no. 7 (2003): 1419–41. http://dx.doi.org/10.5194/angeo-21-1419-2003.

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Abstract. The amplitude and spatial distribution of the coupling currents that flow between Jupiter’s ionosphere and middle magnetosphere, which enforce partial corotation on outward-flowing iogenic plasma, depend on the values of the effective Pedersen conductivity of the jovian ionosphere and the mass outflow rate of iogenic plasma. The values of these parameters are, however, very uncertain. Here we determine how the solutions for the plasma angular velocity and current components depend on these parameters over wide ranges. We consider two models of the poloidal magnetospheric magnetic fie

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Luízar, O., M. V. Stepanova, J. M. Bosqued, E. E. Antonova, and R. A. Kovrazhkin. "Experimental study of the formation of inverted-V structures and their stratification using AUREOL-3 observations." Annales Geophysicae 18, no. 11 (2000): 1399–411. http://dx.doi.org/10.1007/s00585-000-1399-6.

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Abstract. Multiple inverted-V structures are commonly observed on the same auroral zone crossing by a low-altitude orbiting satellite. Such structures appear grouped and apparently result from an ionospheric and/or magnetospheric mechanism of stratification. More than two years of AUREOL-3 satellite observations were analyzed to study their properties and their formation in the framework of the ionosphere-magnetosphere coupling model proposed by Tverskoy. This model predicts some natural periodicity in the electrostatic potential profile (and subsequently in the field-aligned current profiles)

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11

Cowley, S. W. H., C. S. Arridge, E. J. Bunce, et al. "Auroral current systems in Saturn's magnetosphere: comparison of theoretical models with Cassini and HST observations." Annales Geophysicae 26, no. 9 (2008): 2613–30. http://dx.doi.org/10.5194/angeo-26-2613-2008.

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Abstract. The first simultaneous observations of fields and plasmas in Saturn's high-latitude magnetosphere and UV images of the conjugate auroral oval were obtained by the Cassini spacecraft and the Hubble Space Telescope (HST) in January 2007. These data have shown that the southern auroral oval near noon maps to the dayside cusp boundary between open and closed field lines, associated with a major layer of upward-directed field-aligned current (Bunce et al., 2008). The results thus support earlier theoretical discussion and quantitative modelling of magnetosphere-ionosphere coupling at Satu

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12

Bunce, E. J., S. W. H. Cowley, and J. A. Wild. "Azimuthal magnetic fields in Saturn’s magnetosphere: effects associated with plasma sub-corotation and the magnetopause-tail current system." Annales Geophysicae 21, no. 8 (2003): 1709–22. http://dx.doi.org/10.5194/angeo-21-1709-2003.

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Abstract. We calculate the azimuthal magnetic fields expected to be present in Saturn’s magnetosphere associated with two physical effects, and compare them with the fields observed during the flybys of the two Voyager spacecraft. The first effect is associated with the magnetosphere-ionosphere coupling currents which result from the sub-corotation of the magnetospheric plasma. This is calculated from empirical models of the plasma flow and magnetic field based on Voyager data, with the effective Pedersen conductivity of Saturn’s ionosphere being treated as an essentially free parameter. This

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13

Rostoker, G., D. Savoie, and T. D. Phan. "Response of magnetosphere-ionosphere current systems to changes in the interplanetary magnetic field." Journal of Geophysical Research 93, A8 (1988): 8633. http://dx.doi.org/10.1029/ja093ia08p08633.

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14

Kivelson, Margaret Galland. "The Current Systems of the Jovian Magnetosphere and Ionosphere and Predictions for Saturn." Space Science Reviews 116, no. 1-2 (2005): 299–318. http://dx.doi.org/10.1007/s11214-005-1959-x.

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15

Alberti, Tommaso, Mirko Piersanti, Antonio Vecchio, et al. "Identification of the different magnetic field contributions during a geomagnetic storm in magnetospheric and ground observations." Annales Geophysicae 34, no. 11 (2016): 1069–84. http://dx.doi.org/10.5194/angeo-34-1069-2016.

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Abstract. We used the empirical mode decomposition (EMD) to investigate the time variation of the magnetospheric and ground-based observations of the Earth's magnetic field during both quiet and disturbed periods. We found two timescale variations in magnetospheric data which are associated with different magnetospheric current systems and the characteristic diurnal orbital variation, respectively. On the ground we identified three timescale variations related to the solar-wind–magnetosphere high-frequency interactions, the ionospheric processes, and the internal dynamics of the magnetosphere.

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16

Nichols, J. D., and S. W. H. Cowley. "Magnetosphere-ionosphere coupling currents in Jupiter's middle magnetosphere: effect of precipitation-induced enhancement of the ionospheric Pedersen conductivity." Annales Geophysicae 22, no. 5 (2004): 1799–827. http://dx.doi.org/10.5194/angeo-22-1799-2004.

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Abstract. We consider the effect of precipitation-induced enhancement of the Jovian ionospheric Pedersen conductivity on the magnetosphere-ionosphere coupling current system which is associated with the breakdown of the corotation of iogenic plasma in Jupiter's middle magnetosphere. In previous studies the Pedersen conductivity has been taken to be simply a constant, while it is expected to be significantly enhanced in the regions of upward-directed auroral field-aligned current, implying downward precipitating electrons. We develop an empirical model of the modulation of the Pedersen conducti

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17

Burrell, Angeline G., Gareth Chisham, Stephen E. Milan, et al. "AMPERE polar cap boundaries." Annales Geophysicae 38, no. 2 (2020): 481–90. http://dx.doi.org/10.5194/angeo-38-481-2020.

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Abstract. The high-latitude atmosphere is a dynamic region with processes that respond to forcing from the Sun, magnetosphere, neutral atmosphere, and ionosphere. Historically, the dominance of magnetosphere–ionosphere interactions has motivated upper atmospheric studies to use magnetic coordinates when examining magnetosphere–ionosphere–thermosphere coupling processes. However, there are significant differences between the dominant interactions within the polar cap, auroral oval, and equatorward of the auroral oval. Organising data relative to these boundaries has been shown to improve climat

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18

Consolini, Giuseppe, Paola De Michelis, Igino Coco, et al. "Sign-Singularity Analysis of Field-Aligned Currents in the Ionosphere." Atmosphere 12, no. 6 (2021): 708. http://dx.doi.org/10.3390/atmos12060708.

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Field-aligned currents (FACs) flowing in the auroral ionosphere are a complex system of upward and downward currents, which play a fundamental role in the magnetosphere–ionosphere coupling and in the ionospheric heating. Here, using data from the ESA-Swarm multi-satellite mission, we studied the complex structure of FACs by investigating sign-singularity scaling features for two different conditions of a high-latitude substorm activity level as monitored by the AE index. The results clearly showed the sign-singular character of FACs supporting the complex and filamentary nature of these curren

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19

Moretto, T., N. Olsen, P. Ritter, and G. Lu. "Investigating the auroral electrojets with low altitude polar orbiting satellites." Annales Geophysicae 20, no. 7 (2002): 1049–61. http://dx.doi.org/10.5194/angeo-20-1049-2002.

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Abstract. Three geomagnetic satellite missions currently provide high precision magnetic field measurements from low altitude polar orbiting spacecraft. We demonstrate how these data can be used to determine the intensity and location of the horizontal currents that flow in the ionosphere, predominantly in the auroral electrojets. First, we examine the results during a recent geomagnetic storm. The currents derived from two satellites at different altitudes are in very good agreement, which verifies good stability of the method. Further, a very high degree of correlation (correlation coefficie

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20

Lopez, Ramon E., and Daniel N. Baker. "Evidence for Particle Acceleration During Magnetospheric Substorms." International Astronomical Union Colloquium 142 (1994): 531–39. http://dx.doi.org/10.1017/s0252921100077770.

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AbstractMagnetospheric substorms represent the episodic dissipation of energy stored in the geomagnetic tail that was previously extracted from the solar wind. This energy release produces activity throughout the entire magnetosphere-ionosphere system, and it results in a wide variety of phenomena such as auroral intensifications and the generation of new current systems. All of these phenomena involve the acceleration of particles, sometimes up to several MeV. In this paper we present a brief overview of substorm phenomenology. We then review some of the evidence for particle acceleration in

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21

Gjerloev, J. W., S. Ohtani, T. Iijima, B. Anderson, J. Slavin, and G. Le. "Characteristics of the terrestrial field-aligned current system." Annales Geophysicae 29, no. 10 (2011): 1713–29. http://dx.doi.org/10.5194/angeo-29-1713-2011.

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Abstract. We present the first ever comprehensive statistical study of the spatiotemporal characteristics of field-aligned currents in the terrestrial magnetosphere-ionosphere system using multi point measurements. We determine how the FAC density, variability and scale size are coupled. The three ST 5 satellites were in a pearls-on-a-string formation making measurements of the magnetic field with variable inter-spacecraft separations ranging from a few seconds to about 10 min. More than 4700 sets of satellite passes are analyzed using a robust correlation analysis aimed at determining the var

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Sandholt, P. E., and C. J. Farrugia. "Plasma flows, Birkeland currents and auroral forms in relation to the Svalgaard-Mansurov effect." Annales Geophysicae 30, no. 5 (2012): 817–30. http://dx.doi.org/10.5194/angeo-30-817-2012.

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Abstract. The traditional explanation of the polar cap magnetic deflections, referred to as the Svalgaard-Mansurov effect, is in terms of currents associated with ionospheric flow resulting from the release of magnetic tension on newly open magnetic field lines. In this study, we aim at an updated description of the sources of the Svalgaard-Mansurov effect based on recent observations of configurations of plasma flow channels, Birkeland current systems and aurorae in the magnetosphere-ionosphere system. Central to our description is the distinction between two different flow channels (FC 1 and

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de Villiers, J. S., and P. J. Cilliers. "Applying inversion techniques to derive source currents and geoelectric fields for geomagnetically induced current calculations." Annales Geophysicae 32, no. 10 (2014): 1263–75. http://dx.doi.org/10.5194/angeo-32-1263-2014.

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Abstract. This research focuses on the inversion of geomagnetic variation field measurement to obtain source currents in the ionosphere. During a geomagnetic disturbance, the ionospheric currents create magnetic field variations that induce geoelectric fields, which drive geomagnetically induced currents (GIC) in power systems. These GIC may disturb the operation of power systems and cause damage to grounded power transformers. The geoelectric fields at any location of interest can be determined from the source currents in the ionosphere through a solution of the forward problem. Line currents

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Belehaki, A., I. Tsagouri, and H. Mavromichalaki. "Study of the longitudinal expansion velocity of the substorm current wedge." Annales Geophysicae 16, no. 11 (1998): 1423–33. http://dx.doi.org/10.1007/s00585-998-1423-9.

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Abstract. In this work we examine simultaneous observations from the two geosynchronous satellites GOES-5 and GOES-6 located at 282°E and 265°E respectively, and from middle and low latitude ground observatories located within 250°E and 294°E geographic longitude, during isolated substorms of moderate activity. The spatial distribution of our observation points allows us to make a detailed study of the azimuthal expansion of the substorm current wedge. The data analysis shows evidence that the substorm initiation and development mechanism include the cross-tail current diversion/ disruption, t

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25

Giannattasio, Fabio, Alessio Pignalberi, Paola De Michelis, et al. "Parallel Electrical Conductivity at Low and Middle Latitudes in the Topside Ionosphere Derived from CSES-01 Measurements." Remote Sensing 14, no. 20 (2022): 5079. http://dx.doi.org/10.3390/rs14205079.

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The study of electrical currents in the topside ionosphere is of great importance, as it may allow a better understanding of the processes involved in the Sun–Earth interaction and magnetosphere–ionosphere–thermosphere coupling, two crucial aspects debated by the Space Weather scientific community. In this context, investigating the electrical conductivity parallel to the geomagnetic field in the topside ionosphere is of primary importance because: (1) it provides information on the capability of the ionosphere to conduct currents; (2) it relates current density and electric field through Ohm’

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Apatenkov, S. V., V. A. Sergeev, R. Pirjola, and A. Viljanen. "Evaluation of the geometry of ionospheric current systems related to rapid geomagnetic variations." Annales Geophysicae 22, no. 1 (2004): 63–72. http://dx.doi.org/10.5194/angeo-22-63-2004.

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Abstract. To learn about the geometry and sources of the ionospheric current systems which generate strong geomagnetically induced currents, we categorize differential equivalent current systems (DEC) for events with strong dB/dt by decomposing them into the contributions of electrojet-type and vortex-type elementary systems. By solving the inverse problem we obtain amplitudes and locations of these elementary current systems. One-minute differences of the geomagnetic field values at the IMAGE magnetometer network in 1996–2000 are analysed to study the spatial distributions of large dB/dt even

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Tsurutani, Bruce T., and Rajkumar Hajra. "Energetics of Shock-triggered Supersubstorms (SML < −2500 nT)." Astrophysical Journal 946, no. 1 (2023): 17. http://dx.doi.org/10.3847/1538-4357/acb143.

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Abstract The solar wind energy input and dissipation in the magnetospheric–ionospheric systems of 17 supersubstorms (SSSs: SML < −2500 nT) triggered by interplanetary shocks during solar cycles 23 and 24 are studied in detail. The SSS events had durations ranging from ∼42 minutes to ∼6 hr, and SML intensities ranging from −2522 nT to −4143 nT. Shock compression greatly strengthens the upstream interplanetary magnetic field southward component (B s), and thus, through magnetic reconnection at the Earth’s dayside magnetopause, greatly enhances the solar wind energy input into the magnetospher

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Ritter, P., H. Lühr, A. Viljanen, O. Amm, A. Pulkkinen, and I. Sillanpää. "Ionospheric currents estimated simultaneously from CHAMP satelliteand IMAGE ground-based magnetic field measurements: a statisticalstudy at auroral latitudes." Annales Geophysicae 22, no. 2 (2004): 417–30. http://dx.doi.org/10.5194/angeo-22-417-2004.

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Abstract. One important contribution to the magnetic field measured at satellite altitude and at ground level comes from the external currents. We used the total field data sampled by the Overhauser Magnetometer on CHAMP and the horizontal magnetic field measurements of the IMAGE ground-based magnetometer network to study the ionospheric Hall current system in the auroral regions. For the CHAMP data a current model consisting of a series of lines and placed at a height of 110km is fitted to the magnetic field signature sampled on the passage across the polar region. The derived current distrib

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Baumgardner, J., J. Wroten, J. Semeter, et al. "A very bright SAR arc: implications for extreme magnetosphere-ionosphere coupling." Annales Geophysicae 25, no. 12 (2007): 2593–608. http://dx.doi.org/10.5194/angeo-25-2593-2007.

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Abstract. In contrast to the polar aurora visible during geomagnetic storms, stable auroral red (SAR) arcs offer a sub-visual manifestation of direct magnetosphere-ionosphere (M-I) coupling at midlatitudes. The SAR arc emission at 6300 Å is driven by field-aligned magnetospheric energy transport from ring current/plasmapause locations into the ionosphere-thermosphere system. The first SAR arc was observed at the dawn of the space age (1956), and the typical brightness levels and occurrence patterns obtained from subsequent decades of observations appear to be consistent with the downward heat

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Тroshichev, O. A., S. A. Dolgacheva, D. A. Sormakov, and N. А. Stepanov. "Different origins of magnetic disturbances during substorm growth and expansion phases and insufficiency of the AL index as their sole measure." Arctic and Antarctic Research 70, no. 3 (2024): 373–90. http://dx.doi.org/10.30758/0555-2648-2024-70-3-373-390.

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The paper examines the relationship between the PC index, characterizing the solar wind energy input into the magnetosphere, and the AL index, characterizing the magnetic substorm intensity for the expansion phase of isolated substorms recorded in 1998–2017. Magnetic disturbances in the course of the expansion phase are produced by the DP11 current system with a powerful westward electrojet disposed in the midnight auroral zone. It is generally accepted that this electrojet is generated by the “substorm current wedge” system of fieldaligned currents (SCW FAC) providing closure of the magnetota

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Kakad, Bharati, Amar Kakad, Durbha Sai Ramesh, and Gurbax S. Lakhina. "Diminishing activity of recent solar cycles (22–24) and their impact on geospace." Journal of Space Weather and Space Climate 9 (2019): A1. http://dx.doi.org/10.1051/swsc/2018048.

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This study examines the variation of different energies linked with the Sun and the Earth’s magnetosphere-ionosphere systems for solar cycles (SCs) 22–24 for which the gradual decrease in the solar activity is noticed. Firstly, we investigated the variation of solar magnetic energy density (SMED) for SCs 21–24 and its relation to the solar activity. We observed distinct double peak structures in SMED for the past four SCs, 21–24. This feature is consistent with noticeable asymmetry in their two peaks. For SCs 22–24 a significant decrease is observed in the integrated SMED of each SC. This redu

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Pulkkinen, A., A. Thomson, E. Clarke, and A. McKay. "April 2000 geomagnetic storm: ionospheric drivers of large geomagnetically induced currents." Annales Geophysicae 21, no. 3 (2003): 709–17. http://dx.doi.org/10.5194/angeo-21-709-2003.

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Abstract. Geomagnetically induced currents (GIC) flowing in technological systems on the ground are a direct manifestation of space weather. Due to the proximity of very dynamic ionospheric current systems, GIC are of special interest at high latitudes, where they have been known to cause problems, for example, for normal operation of power transmission systems and buried pipelines. The basic physics underlying GIC, i.e. the magnetosphere – ionosphere interaction and electromagnetic induction in the ground, is already quite well known. However, no detailed study of the drivers of GIC has been

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Feldstein, Y. I., L. I. Gromova, A. Grafe, et al. "Auroral electrojet dynamics during magnetic storms, connection with plasma precipitation and large-scale structure of the magnetospheric magnetic field." Annales Geophysicae 17, no. 4 (1999): 497–507. http://dx.doi.org/10.1007/s00585-999-0497-3.

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Abstract. Effect of the equatorward shift of the eastward and westward electrojets during magnetic storms main phase is analyzed based on the meridional chains of magnetic observatories EISCAT and IMAGE and several Russian observatories (geomagnetic longitude ~110°, corrected geomagnetic latitudes 74°F 51°.) Magnetic storms of various Dst index intensity where the main phase falls on 1000 UT - 2400 UT interval were selected so that one of the observatory chains was located in the afternoon - near midnight sector of MLT. The eastward electrojet center shifts equatorward with Dst intensity incre

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Neudegg, D. A., S. W. H. Cowley, K. A. McWilliams, et al. "The UV aurora and ionospheric flows during flux transfer events." Annales Geophysicae 19, no. 2 (2001): 179–88. http://dx.doi.org/10.5194/angeo-19-179-2001.

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Abstract. Far Ultra Violet (FUV) signatures in the polar ionosphere during a period of magnetopause reconnection are compared with ionospheric flows measured in the cusp ‘throat’ and dusk cell by the CUTLASS Hankasalmi HF radar. Regions of peak FUV emission in the 130.4 nm and 135.6 nm range, observed by the Polar spacecraft’s VIS Earth Camera, consistently lie at the turning point of the flows from the dusk cell, poleward into the throat, and at the equatorward edge of the region of high and varied radar spectral-width associated with the cusp. The Equator-S spacecraft was near the magnetopau

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Boutsi, Adamantia Zoe, Constantinos Papadimitriou, Georgios Balasis, Christina Brinou, Emmeleia Zampa, and Omiros Giannakis. "Dynamical Complexity in Geomagnetically Induced Current Activity Indices Using Block Entropy." Entropy 27, no. 2 (2025): 172. https://doi.org/10.3390/e27020172.

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Geomagnetically Induced Currents (GICs) are a manifestation of space weather events at ground level. GICs have the potential to cause power failures in electric grids. The GIC index is a proxy of the ground geoelectric field derived solely from geomagnetic field data. Information theory can be used to shed light on the dynamics of complex systems, such as the coupled solar wind–magnetosphere–ionosphere–ground system. We performed block entropy analysis of the GIC activity indices at middle-latitude European observatories around the St. Patrick’s Day March 2015 intense magnetic storm and Mother

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Vanhamäki, H., O. Amm, and A. Viljanen. "Role of inductive electric fields and currents in dynamical ionospheric situations." Annales Geophysicae 25, no. 2 (2007): 437–55. http://dx.doi.org/10.5194/angeo-25-437-2007.

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Abstract. We study the role of ionospheric induction in different commonly observed ionospheric situations. These include an intensifying electrojet, westward travelling surge (WTS) and Ω-band. We use data based, realistic models for these phenomena and calculate the inductive electric fields that are created due to the temporal variations of ionospheric currents. The ionospheric induction problem is solved using a new calculation technique that can handle non-uniform, time-dependent conductances and electric fields of any geometry. We find that in some situations inductive effects are not neg

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Mishin, V. M., V. V. Mishin, S. B. Lunyushkin, J. Y. Wang, and A. V. Moiseev. "27 August 2001 substorm: Preonset phenomena, two main onsets, field-aligned current systems, and plasma flow channels in the ionosphere and in the magnetosphere." Journal of Geophysical Research: Space Physics 122, no. 5 (2017): 4988–5007. http://dx.doi.org/10.1002/2017ja023915.

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Wild, J. A., S. E. Milan, C. J. Owen, et al. "The location of the open-closed magnetic field line boundary in the dawn sector auroral ionosphere." Annales Geophysicae 22, no. 10 (2004): 3625–39. http://dx.doi.org/10.5194/angeo-22-3625-2004.

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Abstract. As a measure of the degree of coupling between the solar wind-magnetosphere-ionosphere systems, the rate at which the size of the polar cap (the region corresponding to ionospheric termini of open magnetic flux tubes) varies is of prime importance. However, a reliable technique by which the extent of the polar cap might be routinely monitored has yet to be developed. Current techniques provide particularly ambiguous indications of the polar cap boundary in the dawn sector. We present a case study of space- and ground-based observations of the dawn-sector auroral zone and attempt to d

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Peng, Yongxin. "Advancements and Limitations in Geomagnetic Storm Prediction Models." Theoretical and Natural Science 81, no. 1 (2025): 52–58. https://doi.org/10.54254/2753-8818/2025.21052.

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With the rapid increase in satellite launches and frequent space activities, the impact of space weather on human endeavors has become increasingly significant, prompting greater attention to space weather prediction. Geomagnetic storms, driven by solar wind and coronal mass ejections, significantly affect Earth's magnetosphere and ionosphere, necessitating accurate and timely predictions. Despite advancements in physical models, statistical methods, and machine learning techniques, current prediction methods face challenges in balancing accuracy, timeliness, and computational efficiency. This

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Amm, O., A. Aikio, J. M. Bosqued, et al. "Mesoscale structure of a morning sector ionospheric shear flow region determined by conjugate Cluster II and MIRACLE ground-based observations." Annales Geophysicae 21, no. 8 (2003): 1737–51. http://dx.doi.org/10.5194/angeo-21-1737-2003.

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Abstract. We analyse a conjunction event of the Cluster II spacecraft with the MIRACLE ground-based instrument net-work in northern Fennoscandia on 6 February 2001, between 23:00 and 00:00 UT. Shortly after the spacecraft were located at perigee, the Cluster II satellites’ magnetic footpoints move northwards over Scandinavia and Svalbard, almost perfectly aligned with the central chain of the IMAGE magnetometer network, and cross a morning sector ionospheric shear zone during this passage. In this study we focus on the mesoscale structure of the ionosphere. Ionospheric conductances, true horiz

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Feldstein, Y. I., L. I. Gromova, J. Woch, et al. "Structure of the auroral precipitation region in the dawn sector: relationship to convection reversal boundaries and field-aligned currents." Annales Geophysicae 19, no. 5 (2001): 495–519. http://dx.doi.org/10.5194/angeo-19-495-2001.

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Abstract. Abstract. Simultaneous DMSP F7 and Viking satellite measurements of the dawnside high-latitude auroral energy electron and ion precipitation show that the region of the low and middle altitude auroral precipitation consists of three characteristic plasma regimes. The recommendation of the IAGA Working Group IIF/III4 at the IAGA Assembly in Boulder, July 1995 to decouple the nomenclature of ionospheric populations from magnetospheric population is used for their notation. The most equatorial regime is the Diffuse Auroral Zone (DAZ) of diffuse spatially unstructured precipitating elect

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Alberti, Tommaso, Davide Faranda, Giuseppe Consolini, Paola De Michelis, Reik V. Donner, and Vincenzo Carbone. "Concurrent Effects between Geomagnetic Storms and Magnetospheric Substorms." Universe 8, no. 4 (2022): 226. http://dx.doi.org/10.3390/universe8040226.

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An accurate understanding of dissimilarities in geomagnetic variability between quiet and disturbed periods has the potential to vastly improve space weather diagnosis. In this work, we exploit some recently developed methods of dynamical system theory to provide new insights and conceptual ideas in space weather science. In particular, we study the co-variation and recurrence statistics of two geomagnetic indices, SYM-H and AL, that measure the intensity of the globally symmetric component of the equatorial electrojet and that of the westward auroral electrojet, respectively. We find that the

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Kellinsalmi, Mirjam, Ari Viljanen, Liisa Juusola, and Sebastian Käki. "The time derivative of the geomagnetic field has a short memory." Annales Geophysicae 40, no. 4 (2022): 545–62. http://dx.doi.org/10.5194/angeo-40-545-2022.

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Abstract. Solar eruptions and other types of space weather effects can pose a hazard to the high voltage power grids via geomagnetically induced currents (GICs). In worst cases, they can even cause large-scale power outages. GICs are a complex phenomenon, closely related to the time derivative of the geomagnetic field. However, the behavior of the time derivative is chaotic and has proven to be tricky to predict. In our study, we look at the dynamics of the geomagnetic field during active space weather. We try to characterize the magnetic field behavior, to better understand the drivers behind

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Johansson, T., T. Karlsson, G. Marklund, S. Figueiredo, P. A. Lindqvist, and S. Buchert. "A statistical study of intense electric fields at 4−7 R<sub><i>E</i></sub> geocentric distance using Cluster." Annales Geophysicae 23, no. 7 (2005): 2579–88. http://dx.doi.org/10.5194/angeo-23-2579-2005.

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Abstract. Intense high-latitude electric fields (>150 mV/m mapped to ionospheric altitude) at 4–7 RE geocentric distance have been investigated in a statistical study, using data from the Cluster satellites. The orbit of the Cluster satellites limits the data collection at these altitudes to high latitudes, including the poleward part of the auroral oval. The occurrence and distribution of the selected events have been used to characterize the intense electric fields and to investigate their dependance on parameters such as MLT, CGLat, altitude, and also Kp. Peaks in the local time distribu

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Bannister, N. P., E. J. Bunce, S. W. H. Cowley, et al. "A Wide Field Auroral Imager (WFAI) for low Earth orbit missions." Annales Geophysicae 25, no. 2 (2007): 519–32. http://dx.doi.org/10.5194/angeo-25-519-2007.

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Abstract. A comprehensive understanding of the solar wind interaction with Earth's coupled magnetosphere-ionosphere system requires an ability to observe the charged particle environment and auroral activity from the same platform, generating particle and photon image data which are matched in time and location. While unambiguous identification of the particles giving rise to the aurora requires a Low Earth Orbit satellite, obtaining adequate spatial coverage of aurorae with the relatively limited field of view of current space bourne auroral imaging systems requires much higher orbits. A goal

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Sarafopoulos, D. V. "Distinct solar wind pressure pulses producing convection twin-vortex systems in the ionosphere." Annales Geophysicae 22, no. 6 (2004): 2201–11. http://dx.doi.org/10.5194/angeo-22-2201-2004.

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Abstract. We provide conclusive observational evidence demonstrating that a solar wind pressure pulse produces a twin-vortex system of ionospheric currents, while a stepwise pressure increase/decrease creates a single vortex structure, at high-latitude ground magnetograms. Multi-satellite (Wind, Geotail, Interball, IMP 8 and GOES 8) and multi-instrument observations of plasma and magnetic field confirm with in situ measurements that solar wind inherent pressure pulses and stepwise variations strike on the Earth's magnetosphere in a global scale. The ground signatures are scrutinized in detail

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Zhang, Q. H., M. W. Dunlop, R. Holme, and E. E. Woodfield. "Comparison of eight years magnetic field data from Cluster with Tsyganenko models in the inner magnetosphere." Annales Geophysicae 28, no. 1 (2010): 309–26. http://dx.doi.org/10.5194/angeo-28-309-2010.

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Abstract. Eight years of magnetic field data, taken while the four Cluster spacecraft pass through, or adjacent to, the equatorial ring current, have been surveyed to investigate the effects on the Earth's magnetic field of the externally driven current systems connecting the ionosphere, cusp and ring current regions. This study extends previous work to cover a greater range of orbit location and external conditions. We compare the modeled magnetic field from different global field models (Tsyganenko, 1989, 1996, and 2001, hereafter T89, T96 and T01) with data from the four Cluster spacecraft.

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Корсаков, А. А., та В. И. Козлов. "Регистрация ионосферных возмущений с помощью приёма сигналов радиостанций РСДН-20". Vestnik of Volga State University of Technology. Series Radio Engineering and Infocommunication Systems, № 3(59) (20 листопада 2023): 6–20. https://doi.org/10.25686/2306-2819.2023.3.6.

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При мониторинге грозовой активности возникает неоднозначность интерпретации регистрируемых вариаций интенсивности естественных ОНЧ-сигналов. Неоднозначность можно исключить при одновременном приёме со схожих радиотрасс естественных и эталонных ОНЧ-радиосигналов. Приведены методика и результаты регистрации интенсивности радиошума, амплитуды и фазы радиосигналов навигационной системы РСДН-20 на частоте 11,904 кГц. Оценка межгодовых вариаций интенсивности источников радиошума в летний период с 2009 по 2017 гг. показала нарастание на 4 дБ днём и ночью. Проведена адаптация параметров регрессионной

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Le, Guan, Delores J. Knipp, Lutz Rastätter, et al. "Next generation magnetic field measurements from low-earth orbit satellites enable enhanced space weather operations." Frontiers in Astronomy and Space Sciences 9 (November 18, 2022). http://dx.doi.org/10.3389/fspas.2022.1076892.

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Large-scale current systems in the ionosphere and the magnetosphere are intimately controlled by the solar wind-magnetosphere interaction and the magnetosphere-ionosphere coupling. During space weather events, these currents reconfigure and intensify significantly in response to enhanced solar wind-magnetosphere interaction, facilitating explosive energy input from the magnetosphere into the ionosphere-thermosphere system and inducing electric current surges in electric power systems on the ground. Therefore, measurements of magnetic manifestations associated with the dynamic changes of the cu

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Consolini, Giuseppe, Michelis Paola De, Igino Coco, et al. "Sign-Singularity Analysis of Field-Aligned Currents in the Ionosphere." May 31, 2021. https://doi.org/10.3390/atmos12060708.

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Field-aligned currents (FACs) flowing in the auroral ionosphere are a complex system of upward and downward currents, which play a fundamental role in the magnetosphere–ionosphere coupling and in the ionospheric heating. Here, using data from the ESA-Swarm multi-satellite mission, we studied the complex structure of FACs by investigating sign-singularity scaling features for two different conditions of a high-latitude substorm activity level as monitored by the AE index. The results clearly showed the sign-singular character of FACs supporting the complex and filamentary nature of these curren

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